Replaceable and/or collapsible edge ring assemblies for plasma sheath tuning incorporating edge ring positioning and centering features

ABSTRACT

A first edge ring for a substrate support is provided. The first edge ring includes an annular-shaped body and one or more lift pin receiving elements. The annular-shaped body is sized and shaped to surround an upper portion of the substrate support. The annular-shaped body defines an upper surface, a lower surface, a radially inner surface, and a radially outer surface. The one or more lift pin receiving elements are disposed along the lower surface of the annular-shaped body and sized and shaped to receive and provide kinematic coupling with top ends respectively of three or more lift pins.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/718,112, filed on Aug. 13, 2018. The entire disclosure of theapplication referenced above is incorporated herein by reference.

FIELD

The present disclosure relates to moveable edge rings in substrateprocessing systems.

BACKGROUND

The background description provided here is for the purpose of generallypresenting the context of the disclosure. Work of the presently namedinventors, to the extent it is described in this background section, aswell as aspects of the description that may not otherwise qualify asprior art at the time of filing, are neither expressly nor impliedlyadmitted as prior art against the present disclosure.

Substrate processing systems may be used to treat substrates such assemiconductor wafers. Example processes that may be performed on asubstrate include, but are not limited to, chemical vapor deposition(CVD), atomic layer deposition (ALD), conductor etch, and/or other etch,deposition, or cleaning processes. A substrate may be arranged on asubstrate support, such as a pedestal, an electrostatic chuck (ESC),etc. in a processing chamber of the substrate processing system. Duringetching, gas mixtures including one or more precursors may be introducedinto the processing chamber and plasma may be used to initiate chemicalreactions.

The substrate support may include a ceramic layer arranged to support awafer. For example, the wafer may be clamped to the ceramic layer duringprocessing. The substrate support may include an edge ring arrangedaround an outer portion (e.g., outside of and/or adjacent to aperimeter) of the substrate support. The edge ring may be provided toconfine plasma to a volume above the substrate, protect the substratesupport from erosion caused by the plasma, shape and position a plasmasheath, etc.

SUMMARY

A first edge ring for a substrate support is provided. The first edgering includes an annular-shaped body and one or more lift pin receivingelements. The annular-shaped body is sized and shaped to surround anupper portion of the substrate support. The annular-shaped body definesan upper surface, a lower surface, a radially inner surface, and aradially outer surface. The one or more lift pin receiving elements aredisposed along the lower surface of the annular-shaped body and sizedand shaped to receive and provide kinematic coupling with top endsrespectively of three or more lift pins.

In other features, the collapsible edge ring assembly for a substratesupport is provided. The collapsible edge ring assembly includes edgerings and three or more alignment and spacing elements. The edge ringsare arranged in a stack. At least one of the edge rings is shaped andsized to surround an upper portion of the substrate support. The edgerings include a top edge ring and at least one intermediate edge ring.The three or more ring alignment and spacing elements contact each ofthe edge rings and are configured to maintain radial alignment andvertical spacing of the edge rings. The three or more ring alignment andspacing elements are configured to lift the at least one intermediateedge ring while the top edge ring is lifted.

In other features, a collapsible edge ring assembly for a substratesupport is provided. The collapsible edge ring assembly includesmultiple edge rings and a stepped outer edge ring. The edge rings arearranged in a stack. At least one of the edge rings is shaped and sizedto surround an upper portion of the substrate support. The edge ringsinclude a top edge ring and at least one intermediate edge ring. Thestepped outer edge ring includes levels. The edge rings are disposedrespectively on the levels. The stepped outer edge ring is configured tomaintain radial alignment and vertical spacing of the plurality of edgerings. The stepped outer edge ring is configured to lift the at leastone intermediate edge ring while the top edge ring is lifted.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of an example of a substrateprocessing system including an edge ring assembly in accordance with anembodiment of the present disclosure;

FIG. 2A is a cross-sectional side view of an example of a moveable edgering having a lift pin receiving element in accordance with anembodiment of the present disclosure;

FIG. 2B is a cross-sectional side view of the moveable edge ring of FIG.2A in a raised position;

FIG. 3A is a radial cross-sectional view of an example of a portion ofan edge ring assembly, a substrate support and a substrate in accordancewith an embodiment of the present disclosure;

FIG. 3B is an azimuthal cross-sectional view through section line A-A ofFIG. 3A;

FIG. 4 is an example of an azimuthal cross-sectional view of a portionof a top edge ring and corresponding lift pin illustrating pin-to-grooveinteraction in accordance with an embodiment of the present disclosure;

FIG. 5 is a perspective view of an example of a lift pin receivingelement having a ‘V’-shaped groove in accordance with an embodiment ofthe present disclosure;

FIG. 6 is a bottom view of an example of a top edge ring having multiplelift pin receiving elements with respective ‘V’-shaped grooves inaccordance with an embodiment of the present disclosure;

FIG. 7 is a cross-sectional side view of a portion of a top edge ringillustrating dimensions of a ‘V’-shaped groove in accordance with anembodiment of the present disclosure;

FIG. 8 is a cross-sectional side view of a portion of an edge ring stackillustrating an example of a top edge ring having a lift pin receivingelement in the form of a groove with a flat recessed top portion inaccordance with an embodiment of the present disclosure;

FIG. 9 is a perspective view of the lift pin receiving element of FIG.8;

FIG. 10 is a cross-sectional side view of a portion of an edge ringstack illustrating an example of a top edge ring having lift pinreceiving element in the form of a divot in accordance with anembodiment of the present disclosure;

FIG. 11 is a perspective view of the lift pin receiving element of FIG.10;

FIG. 12 is a cross-sectional side view of an example of an edge ringassembly, substrate support and substrate illustrating an example of atop edge ring with a lift pin receiving element including a groovehaving a recessed top portion with quarter spherically shaped ends inaccordance with an embodiment of the present disclosure;

FIG. 13 is a perspective view of the lift pin receiving element of thetop edge ring of FIG. 12;

FIG. 14 is a cross-sectional side view of an example portion of an edgering assembly, a substrate support and substrate illustratingincorporation of stability elements disposed within the substratesupport and/or one or more edge rings in accordance with an embodimentof the present disclosure;

FIG. 15 is a cross-sectional side view of an example of an edge ringassembly, a substrate support and a substrate illustrating a top edgering with peripherally located lift pin receiving elements in accordancewith an embodiment of the present disclosure;

FIG. 16 is top view of an example of a portion of the top edge ring ofFIG. 15;

FIG. 17 is a bottom view of one of the peripherally located lift pinreceiving elements of FIG. 15;

FIG. 18 is a bottom view of the top edge ring of FIG. 15;

FIG. 19 is a cross-sectional side view of an edge ring system, asubstrate support and a substrate illustrating an example of acollapsible edge ring assembly in accordance with an embodiment of thepresent disclosure;

FIG. 20 is a cross-sectional side view of an example of a portion ofanother collapsible edge ring assembly in a first partially expandedstate and illustrating a corresponding plasma sheath tilt angle inaccordance with an embodiment of the present disclosure;

FIG. 21 is a cross-sectional side view of the portion of the collapsibleedge ring assembly of FIG. 20 in a second partially expanded state andillustrating a corresponding plasma sheath tilt angle;

FIG. 22A is a cross-sectional side view of an example of a portion ofanother collapsible edge ring assembly including a ring alignment andspacing element that is inner disposed and in a collapsed state inaccordance with an embodiment of the present disclosure;

FIG. 22B is a cross-sectional side view of the portion of thecollapsible edge ring assembly of FIG. 22A, where the ring alignment andspacing element is in an expanded state;

FIG. 23A is a cross-sectional side view of an example of a portion ofanother collapsible edge ring assembly including a ring alignment andspacing element in an expanded state in accordance with an embodiment ofthe present disclosure;

FIG. 23B is a bottom view of the collapsible edge ring assembly of FIG.23A;

FIG. 24 is a cross-sectional side view of a portion of an edge ringsystem, a substrate support and a substrate illustrating an example of acollapsible edge ring assembly including edge rings lifted by a steppedouter ring in accordance with an embodiment of the present disclosure;

FIG. 25 is a cross-sectional side view of an example of an edge ringassembly, a substrate support and a substrate illustrating edge ringslifted by stepped lift pins in accordance with an embodiment of thepresent disclosure; and

FIG. 26 is a cross-sectional side view of an example of a portion ofanother collapsible edge ring assembly including a ring alignment andspacing element with telescopic sections in accordance with anembodiment of the present disclosure.

In the drawings, reference numbers may be reused to identify similarand/or identical elements.

DETAILED DESCRIPTION

A substrate support in a substrate processing system may include an edgering. An upper surface of the edge ring may extend above an uppersurface of the substrate support, causing the upper surface of thesubstrate support (and, in some examples, an upper surface of asubstrate (or wafer) arranged on the substrate support) to be recessedrelative to the edge ring. This recess may be referred to as a pocket. Adistance between the upper surface of the edge ring and the uppersurface of the substrate may be referred to as a “pocket depth.” Thepocket depth may be fixed according to a height of the edge ringrelative to the upper surface of the substrate.

Some substrate processing systems may implement a moveable (e.g.,tunable) and/or replaceable edge ring. In one example, a height of theedge ring may be adjusted during processing to control etch uniformity,shape of a plasma sheath, and an ion tilt angle. An actuator raises andlowers the edge ring. In one example, a controller of the substrateprocessing system controls operation of the actuator to adjust a heightof the edge ring during a process and according to a particular recipebeing performed and associated gas injection parameters.

Edge rings and other corresponding components may include consumablematerials that wear/erode over time. Accordingly, the heights of theedge rings may be adjusted to compensate for erosion. The edge rings maybe removable and replaceable to be replaced when in an eroded and/ordamaged state such that the edge rings have unusable geometries. Theterm “removable” as used herein refers to the ability of an edge ring tobe removed from a processing chamber while under vacuum using, forexample, a vacuum transfer arm. The edge ring may be lifted via liftpins to a height at which the vacuum transfer arm is able to move theedge ring out of the corresponding processing chamber and replace theedge ring with another edge ring.

Edge rings can have flat bottom surfaces, which contact top ends of liftpins when placed on the lift pins. Placement on lift pins can vary for asingle edge ring and can be different for different edge rings. Forexample, a first edge ring may be placed relative to the lift pins suchthat the lift pins contact the first edge ring at first points. The liftpins may be raised and lowered multiple times throughout a lifecycle ofthe first edge ring. The positions of the contact points may vary dueto, for example, plasma erosion over time of the first edge ring,horizontal movement of the first edge ring, etc. As a result, relativepositioning of the first edge ring relative to a corresponding substratesupport and a substrate being processed is different. This can affectprocessing of the substrate.

As another example, the first edge ring may be replaced with a secondedge ring. The second edge ring may have the same dimensions as thefirst edge ring when the first edge ring was new and unused. The secondedge ring may be placed relative to the lift pins such that the liftpins contact the second edge ring at second points. The second pointsmay be different than the first points. As a result, relativepositioning of the second edge ring relative to a correspondingsubstrate support and a substrate being processed is different than thatof the first edge ring, which can affect processing of the substrate.

Examples set forth herein include replaceable and/or collapsible edgering assemblies (hereinafter “the assemblies”) for plasma sheath tuningthat include features for predictable, repeatable and consistentpositioning of edge rings such that lift pins contact the edge rings atthe same locations. This is true for a single edge ring that is raisedand lowered multiple times during multiple processes such that lift pinsare moved into contact with the edge ring and moved away from the edgering multiple times. This also holds true for different edge rings,where for example, a first edge ring is replaced with a second edgering.

The assemblies include edge ring positioning, alignment and centeringfeatures, such as kinematic coupling features, stabilizing features,chamfered surfaces, beveled surfaces, stepped lift pins, lift pin setsallocated for respective edge rings, etc. The kinematic couplingfeatures include grooves, pockets, notches, and/or other lift pinreceiving and/or recessed portions of edge rings for receiving liftpins. In some of the examples, the assemblies (also referred to as“kits”) include multiple stacked edge rings that are arranged and heldin alignment via ring alignment and spacing elements. The stabilizingfeatures include stabilizing edge rings, springs, etc.

As used herein, the phrase “kinematic coupling” refers to the use oflift pin receiving elements having constraining features, whichconstrain the lateral movement of corresponding edge rings. Kinematiccoupling does not refer to confining features or features that simplylimit movement in a lateral direction. As an example, kinematic couplingmay be provided by one or more lift pin receiving elements. A groove maybe shaped and sized to contact one or more lift pins. For example, alinear groove may contact, for example, one or two lift pins, wheres asa circular groove may contact three lift pins. The constraining featuresinclude surfaces of the lift pin receiving elements, for example,surfaces of a ‘V’-shaped groove, which contact a corresponding lift pinat two lift pin contact points. Each lift pin contacts one of the liftpin receiving elements at two contact points.

As an example, an edge ring is laterally constrained when the edge ringhas three lift pin receiving elements, where each of the lift pinreceiving elements contacts a respective lift pin at two contact points.In this example, each of the lift pin receiving elements does notcontact the respective lift pin at more than two contact points.Kinematic coupling is not, however, limited to this example. Analternative technique to achieve the same effect involves three liftpins, one which contacts the edge ring at precisely three points (a coneor a pyramid shaped divot), a second which contacts the edge ring atprecisely two points (V-Groove), and a third which makes a single pointof contact. Other similar techniques exist. The end effect of eachexample technique is the same as each technique constrains the edge ringwith precision by making a total of 6 points of contact to achievecomplete control of all 6 degrees of freedom (X, Y, Z, pitch, roll, andyaw). Note that constraining is different than confining. An edge ringmay be confined if, for example, the edge ring includes threecube-shaped notches configured to receive three lift pins. A width ofthe cube-shaped notches may be larger than diameters of the lift pinssuch that a gap exists between the lift pins and the cube-shapednotches. The edge ring may be confined (or limited in lateral movement),but is not constrained.

FIG. 1 shows a substrate processing system 100, which, as an example,may perform etching using RF plasma and/or perform other substrateprocessing operations. The substrate processing system 100 includes aprocessing chamber 102 that encloses some of the components of thesubstrate processing system 100 and contains the RF plasma. Thesubstrate processing chamber 102 includes an upper electrode 104 and asubstrate support 106, such as an electrostatic chuck (ESC). Duringoperation, a substrate 108 is arranged on the substrate support 106.While a specific substrate processing system 100 and chamber 102 areshown as an example, the principles of the present disclosure may beapplied to other types of substrate processing systems and chambers,such as a substrate processing system that generates plasma in-situ,implements remote plasma generation and delivery (e.g., using a plasmatube, a microwave tube), etc.

For example only, the upper electrode 104 may include a gas distributiondevice such as a showerhead 109 that introduces and distributes processgases (e.g., etch process gases). The showerhead 109 may include a stemportion including one end connected to a top surface of the processingchamber 102. A base portion is generally cylindrical and extendsradially outwardly from an opposite end of the stem portion at alocation that is spaced from the top surface of the processing chamber102. A substrate-facing surface or faceplate of the base portion of theshowerhead 109 includes holes through which process gas or purge gasflows. Alternately, the upper electrode 104 may include a conductingplate and the process gases may be introduced in another manner.

The substrate support 106 includes a conductive baseplate 110 that actsas a lower electrode. The baseplate 110 supports a ceramic layer (or topplate) 112. In some examples, the ceramic layer 112 may include aheating layer, such as a ceramic multi-zone heating plate. A thermalresistance layer 114 (e.g., a bond layer) may be arranged between theceramic layer 112 and the baseplate 110. The baseplate 110 may includeone or more coolant channels 116 for flowing coolant through thebaseplate 110.

An RF generating system 120 generates and outputs an RF voltage to oneof the upper electrode 104 and the lower electrode (e.g., the baseplate110 of the substrate support 106). The other one of the upper electrode104 and the baseplate 110 may be DC grounded, AC grounded or floating.For example only, the RF generating system 120 may include an RF voltagegenerator 122 that generates the RF voltage that is fed by a matchingand distribution network 124 to the upper electrode 104 or the baseplate110. In other examples, the plasma may be generated inductively orremotely. Although, as shown for example purposes, the RF generatingsystem 120 corresponds to a capacitively coupled plasma (CCP) system,the principles of the present disclosure may also be implemented inother suitable systems, such as, for example only transformer coupledplasma (TCP) systems, CCP cathode systems, remote microwave plasmageneration and delivery systems, etc.

A gas delivery system 130 includes one or more gas sources 132-1, 132-2,. . . , and 132-N (collectively gas sources 132), where N is an integergreater than zero. The gas sources supply one or more gases (e.g., etchgas, carrier gases, purge gases, etc.) and mixtures thereof. The gassources may also supply purge gas. The gas sources 132 are connected byvalves 134-1, 134-2, . . . , and 134-N (collectively valves 134) andmass flow controllers 136-1, 136-2, . . . , and 136-N (collectively massflow controllers 136) to a manifold 140. An output of the manifold 140is fed to the processing chamber 102. For example only, the output ofthe manifold 140 is fed to the showerhead 109.

A temperature controller 142 may be connected to heating elements, suchas thermal control elements (TCEs) 144 arranged in the ceramic layer112. For example, the heating elements 144 may include, but are notlimited to, macro heating elements corresponding to respective zones ina multi-zone heating plate and/or an array of micro heating elementsdisposed across multiple zones of a multi-zone heating plate. Thetemperature controller 142 may control power to the heating elements 144to control a temperature of the substrate support 106 and the substrate108.

The temperature controller 142 may communicate with a coolant assembly146 to control coolant flow through the channels 116. For example, thecoolant assembly 146 may include a coolant pump and reservoir. Thetemperature controller 142 operates the coolant assembly 146 toselectively flow the coolant through the channels 116 to cool thesubstrate support 106.

A valve 150 and pump 152 may be used to evacuate reactants from theprocessing chamber 102. A system controller 160 may be used to controlcomponents of the substrate processing system 100. A robot 170 may beused to deliver substrates onto, and remove substrates from, thesubstrate support 106. For example, the robot 170 may transfersubstrates between the substrate support 106 and a load lock 172.Although shown as separate controllers, the temperature controller 142may be implemented within the system controller 160. In some examples, aprotective seal 176 may be provided around a perimeter of the thermalresistance layer 114 between the ceramic layer 112 and the baseplate110.

The substrate support 106 includes an edge ring 180. The edge ringsdisclosed herein are annularly-shaped including the edge ring 180. Theedge ring 180 may be a top ring, which may be supported by a bottom ring184. In some examples, the edge ring 180 may be further supported by oneor more middle rings (not shown in FIG. 1) and/or other portions of thesubstrate support 106. The edge ring 180 may include pin receivingelements 182 that receive top ends of lift pins 185. Examples of thelift pin receiving elements 182 and corresponding edge rings and ringalignment and spacing elements are described below with respect to atleast FIGS. 2A-26.

The edge ring 180 is moveable (e.g., moveable upward and downward in avertical direction) relative to the substrate 108. For example, the edgering 180 may be controlled via an actuator responsive to the controller160. In some examples, the edge ring 180 may be vertically moved duringsubstrate processing (i.e., the edge ring 180 may be tunable). In otherexamples, the edge ring 180 may be removable using, for example, therobot 170, via an airlock, while the processing chamber 102 is undervacuum. In still other examples, the edge ring 180 may be both tunableand removable. In other embodiments, the edge ring 180 may beimplemented as a collapsible edge ring assembly, as further describedbelow.

FIGS. 2A and 2B show an example substrate support 200 having a substrate204 arranged thereon is shown. The substrate support 200 may include abase or pedestal having an inner portion (e.g., corresponding to an ESC)208 and an outer portion 212. In examples, the outer portion 212 may beindependent from, and moveable in relation to, the inner portion 208.For example, the outer portion 212 may include a bottom ring 216 and atop edge ring 220. The substrate 204 is arranged on the inner portion208 (e.g., on a ceramic layer (or top plate) 224) for processing. Acontroller 228 controls operation of one or more actuators 232 toselectively raise and lower the edge ring 220. For example, the edgering 220 may be raised and/or lowered to adjust a pocket depth of thesupport 200 during processing. In another example, the edge ring 220 maybe raised to facilitate removal and replacement of the edge ring 220.

For example only, the edge ring 220 is shown in a fully lowered positionin FIG. 2A and in a fully raised position in FIG. 2B. As shown, theactuators 232 correspond to pin actuators configured to selectivelyextend and retract lift pins 236 in a vertical direction. For exampleonly, the edge ring 220 may be formed of ceramic, quartz and/or othersuitable materials (e.g., silicon carbide, yttria, etc.). In FIG. 2A,the controller 228 communicates with the actuators 232 to directly raiseand lower the edge ring 220 via the lift pins 236. In some examples, theinner portion 208 is moveable relative to the outer portion 212.

The edge ring 220 includes lift pin receiving elements 240 that receivetop ends of the lift pins 236. The edge ring 220 may include one or morelift pin receiving elements for receiving three or more lift pins. Inone embodiment, the edge ring 220 includes three lift pin receivingelements that receive respectively three lift pins. The three lift pinreceiving elements may be disposed 120° apart from each other (anexample of this arrangement is shown in FIG. 6). The lift pin receivingelements 240 may include grooves, divots, pockets, notches, recessedregions, and/or other suitable lift pin receiving elements. The contactbetween the lift pin receiving elements 240 and the lift pins provideskinematic coupling which positions the edge ring 220 on the lift pinsand maintains a position of the edge ring 220 in horizontal (or lateral)directions (e.g., in X and Y directions) and vertical directions (e.g.,Z directions). This provides an anti-walk feature. Edge ring “walking”refers to positional drift of a top edge ring relative to a substratebeing processed over time, which leads to a drift in extreme edge (EE)uniformity.

The anti-walk feature aids in preventing the substrate 204 from movinghorizontally: when unclamped (or floating) on the substrate support 200;during thermal cycling; when thermal differences associated withdiffering coefficients of thermal expansion exist; poor de-chucking of asubstrate; and/or during vibration events. Examples of the lift pinreceiving elements are shown in at least FIGS. 3A-13, 15-21 and 25. Whenthe edge ring 220 is raised for tuning during processing as describedabove, the controller 228 is configured to control a tunable range ofthe edge ring 220. In other words, the edge ring 220 may be raised froma fully lowered position (e.g., 0.0 inches (″)) to a fully raisedposition (e.g., 0.25″). The lift pins 236 may be raised a predeterminedamount (e.g., 0.050″) from an initial position before coming in contactwith the edge ring 220.

FIGS. 3A and 3B show a portion 300 of an edge ring assembly 302, asubstrate support 304 and a substrate 306. The edge ring assembly 302may include a top edge ring 308, a middle edge ring 310 and a bottomedge ring 312. The substrate support 304 may include a top plate 314 anda baseplate 318.

The top edge ring 308 is cupped with a top member 319 and an outerflange 320, which extends downward from the top member 319. The topmember 319 includes lift pin receiving elements (one lift pin receivingelement 322 is shown). The lift pin receiving element 322 is located ona bottom side of the top member 319 and faces a lift pin 324, whichextends through the baseplate 318, a hole 328 in the bottom edge ring312, and a hole 329 in the middle edge ring 310. The lift pin 324extends through a hole 330 in the baseplate 318. The outer flange 320protects the middle edge ring 310, an upper portion of the lift pin 324,an upper portion of the bottom edge ring 312, and a portion of thesubstrate support 304 from directly receiving and/or being in contactwith plasma. This prevents erosion and increases life of the middle edgering 310, the lift pin 324, the bottom edge ring 312 and the substratesupport 304. Similarly, the bottom edge ring 312 protects a portion ofthe lift pin 324 and the baseplate 318 from direct exposure and/orcontact with plasma. The hole 329 is oversized to prevent the lift pin324 from contacting the middle edge ring 310.

A top end 332 of the lift pin 324 is received in the lift pin receivingelement 322. The lift pin receiving element 322 may be, for example, a‘V’-shaped groove having half conically shaped (or quarter sphericallyshaped) ends. The ‘V’-shape of the groove can be seen in FIGS. 3B, 4, 5and 7. The top end 332 of the lift pin 324 may be hemi-sphericallyshaped or may have (i) a rounded edge portion 340 that contacts surfaces342, 344 of the lift pin receiving element 322, and (ii) a flat topsurface 346. The top end 332 is shaped such that two points of the liftpin 324 contact the lift pin receiving element 322 and no other portionsof the lift pin 324. The top end 332 may have a flat top surface 346 to:increase ease in manufacturing the lift pin 324 and thus decreasemanufacturing cost; increase yield; and/or prevent the top end 332 fromcontacting a vertex portion (or curved portion) of the lift pinreceiving element 322. The vertex portion is identified with numericaldesignator 400 in FIG. 4. Contact between the top end 332 and the vertexportion 400 is referred to as “bottoming out” the lift pin 324 in the‘V’-shaped groove.

The middle edge ring 310 includes an instep 350 that transitions from afirst top surface 352 to a second top surface 354. The substrate 306 isdisposed on the first top surface 352. The top edge ring 308 is disposedon the second top surface 354. The second top surface 354 is at a lowerlevel than the first top surface 352. The top edge ring 308 may beraised to a level higher than a level of the first top surface 352and/or a level of a top surface of the substrate 306. As an example, thetop edge ring 308 may be lifted 0.24″-0.60″ relative to the middle edgering 310. The top edge ring 308 may be lifted, for example, 0.15″-0.2″above the level of the top surface of the substrate 306. When the topedge ring 308 is in a fully down (or retracted) position, the substrate306 is disposed radially inward of the top edge ring 308. When the topedge ring 308 is in a fully raised (or extended) position, the top edgering 308 may be higher than the substrate 306. The instep 350 (i) aidsin declamping the substrate 306 from the substrate support 304, (ii)aids in maintaining positioning of the top edge ring 308 includingpreventing the top edge ring from tilting relative to the substrate 306,and (iii) aids in preventing the substrate 306 from moving under the topedge ring 308 when, for example, the substrate 306 is not clamped to thesubstrate support 304.

The top edge ring 308 may include one or more of the lift pin receivingelements 322, as shown in FIG. 6. This along with contact withcorresponding lift pins provides kinematic coupling and anti-walkfeatures. The top edge ring 308 is centered relative to the substratesupport 304 based on the interaction between the lift pins and the liftpin receiving elements 322. If the top edge ring 308 is initially placedsuch that the lift pin receiving elements 322 are within a predetermineddistance of the corresponding lift pins, then the lift pin receivingelements 322 move to receive the lift pins, thereby positioning the topedge ring 308. Put another way, if the top edge ring 308 is placedwithin a predetermined distance of a target position (a position wheretop ends of the lift pins are located in the lift pin receivingelements), then the top edge ring 308 moves to the target position. Thisis due to the inclusion of the ‘V’-shaped grooves and may also be due tobeveled opening edges of the lift pin receiving elements. Examplebeveled opening edges are shown in FIGS. 5 and 7. As an example, if thetop edge ring 308 is positioned within ±5% of the target position, thenthe top edge ring 308 moves to the target position defined by the liftpin receiving elements 322. The top edge ring 308 drops into place andis held on the lift pins by gravity.

The kinematic coupling between the lift pin receiving elements of thetop edge ring 308 and the lift pins allows the top edge ring 308 to becentered to a same location relative to the substrate support 304independent of erosion over time of the edge rings 308, 310, 312. Thisconsistent centering occurs due to the uniform erosion (i.e. erosion ata same rate) of the surfaces 342, 344 and uniform erosion of the top end332. The kinematic coupling also allows certain tolerances to be relaxed(i.e. increased). For example, tolerances of the dimensions of the liftpin receiving elements may be increased, since the edge ring 308 ispositioned in approximately a same location relative to the lift pinseach time the edge ring 308 is placed. As another example, gaps betweenthe edge rings 308, 310, 312 may be increased due to the consistentplacement of the edge ring 308 on the lift pins. The uniform erosionmaintains centering of the top edge ring 308 for the usable lifetime ofthe top edge ring 308.

Also, if the top edge ring 308 is not centered on the substrate support304 and/or is not concentric with the substrate 306, then a center ofthe top edge ring 308 is (i) offset from a center of the substratesupport 304 and/or a top plate of the substrate support 304, and/or (ii)offset from a center of the substrate 306. These offsets may bedetermined and will consistently exist. As a result, the controllers142, 160 of FIG. 1 may account for and/or compensate for these offsetswhen processing the substrate 306. This may include adjust parameters,such as gas pressures, electrode voltages, bias voltages, etc. tocompensate for these offsets.

In one embodiment, the edge rings 308, 310, 312 are formed of quartzand/or one or more other suitable non-volatile materials. The lift pin324 may be formed of sapphire and/or one or more other suitable volatilematerials. This minimizes erosion and particle generation duringprocessing. Examples of volatile materials are alumina, silicon carbideand sapphire.

FIG. 4 shows a portion of the top edge ring 308 and corresponding liftpin 324 illustrating pin-to-groove interaction. The top end 332 of thelift pin 324 contacts the surfaces 342, 344 at respectively two points401, 402 via a rounded edge portion 340. This provides minimal contactfor minimal reaction forces. The minimal contact minimizes erosion ofthe surfaces 342, 344 and the top end 332. This radial to flat contactbetween the rounded edge portion 340 and the surfaces 342, 344 followsHertz's Law. As an example, a diameter D1 of the lift pin 324 may be0.040″ and may be up to 0.0250″. In an embodiment, the diameter D1 is0.060″-0.080″. A diameter of the hole 329 in the middle edge ring 310may be 2-3 times the diameter of the lift pin 324. The flat top portion346 of the lift pin 324 does not contact the vertex portion 400.

FIG. 5 shows the lift pin receiving element 322, which includes a‘V’-shaped groove 500 with the surfaces 342, 344 and half conicallyshaped (or quarter spherically shaped) ends 502, 504. The surfaces 342,344 and the ends 502, 504 meet at a vertex portion 506, which may berounded, as shown. The surfaces 342, 344 and the ends 502, 504 havebeveled opening edges 508, 510, 512, 514. The beveled opening edges 508,510, 512, 514 aid in positioning lift pins into the ‘V’-shaped groove500.

FIG. 6 shows the top edge ring 308 having multiple lift pin receivingelements 322, 322′, 322″ including respective ‘V’-shaped grooves havinghalf conically-shaped ends as shown or quarter hemi-spherically shapedends. Each of the ‘V’-shaped grooves allows the corresponding lift pinto move radially relative to the ‘V’-shaped groove, but prevents annularmovement of the corresponding lift pin. Three lift pins 600 are shown,one of which may be the lift pin 324 of FIG. 3A.

FIG. 7 shows a portion of the top edge ring 308 illustrating dimensionsof a ‘V’-shaped groove 700. The ‘V’-shaped groove 700 includes the sidesurfaces 342, 344, a vertex portion 702, and beveled edges 704, 706. Thevertex portion 702 may have a first predetermined radius R1 and thebeveled edges 704, 706 may have respective predetermined radii R2, R3.As an example, the radii R1, R2, R3 may be 0.015″. Radius R1 may bebetween 0.002″ and 0.125″. Radius R2 may be between 0.002″ and 0.125″.Radius R3 may be between 0.002″ and 0.125″. Each of the surfaces 342,344 may be at a predetermined angle A1 relative to a center line 710 ofthe ‘V’-shaped groove 700. The surfaces 342, 344 may be at apredetermined angle A2 relative to each other. As an example, thepredetermined angle A1 may be 45°. The predetermined angle A1 may bebetween 5° and 90°. As an example, the predetermined angle A2 may be90°. The predetermined angle A2 may be between 10° and 180°.

The ‘V’-shaped groove 700 has a predetermined opening width W1. Thebeveled edges 704, 706 have a predetermined opening width W2, which isgreater than W1. As an example the predetermined opening width W1 may be0.104″. The predetermined opening width W1 may be between 0.020″ and0.500″. The predetermined opening width W2 may be between 0.024″ and0.750″. The ‘V’-shaped groove 700 has a predetermined depth DP1. Thedepth DP1 may be between 0.010″ and 0.250″.

A ratio between the depth DP1 and a diameter D1 (shown in FIG. 4) of acorresponding lift pin 324 may be approximately equal to 1 (or 1:1). Theratio between the depth DP1 and the diameter D1 may be between 10:1 and1:8. In an embodiment, the depth DP1 is 0.062″. The depth DP1 may bebetween 0.005″ and 0.250″. A ratio between the width W1 and the diameterD1 may be 2:1. The ratio between the width W2 and the diameter D1 may bebetween 20:1 and 1:4. A ratio between a depth DP2 of the lift pin 324 inthe ‘V’-shaped groove 700 and the depth DP1 may be approximately equalto 5.0:6.2 or 80%, where the depth DP2 is 0.050″ and the depth DP1 is0.062″. The ratio between the depth DP2 and the depth DP1 may be between10:1 and 99:100. The depth DP2 may be between 0.001″ and 0.500″. In anembodiment, the depth DP2 is 0.050″.

In an embodiment, the angle A2 is 90°, the depth DP2 is 0.050″, thediameter D1 is 0.060″, the depth DP1 is 0.0062″, and the width W1 is0.104″. This: provides two points of contact between the lift pin 324and the ‘V’-shaped groove 700; provides an appropriate amount of spacebetween a top of the lift pin 324 and the vertex portion 702 (or top) ofthe ‘V’-shaped groove 700 to prevent bottoming out; maximizes athickness T1 between the ‘V’-shaped groove 700 and a top surface of thetop edge ring 308; and provides an opening width sized to provide anappropriate amount of placement tolerance for positioning and centeringthe corresponding top edge ring 308 relative to a substrate support andguiding the lift pin 324 into the ‘V’-shaped groove 700. The edge ring308 may have an overall thickness T2 and a top surface to ‘V’-shapedgroove thickness T1. The thickness T2 may be between 0.025″ and 10″. Thethickness T1 may be between 0.02″ and 9.995″. In an embodiment, thethickness T2 is 0.145″ and the thickness T1 is 0.083″.

The larger the angle A2, the more likely that the lift pin 324 willbottom out and contact the vertex portion 702. The smaller the angle A2,the deeper is the groove 700 and the smaller is the thickness T1, whichreduces lifetime of the top edge ring 308. The wider the width W1 of theopening, while maintaining the angle A2 at a constant value, the smallerthe thickness T1 and the less restrictive the horizontal placement ofthe lift pin 324. The narrower the width W1, while maintaining the angleA2 at constant value, the larger the thickness T1 and the morerestrictive the horizontal placement of the lift pin 324.

FIG. 8 shows a portion 800 of an edge ring stack illustrating an exampleof a top edge ring 802 having a lift pin receiving element 803 in theform of a groove with a flat recessed top portion 804. This style liftpin receiving element may replace or be used in combination with thelift pin receiving element shown in FIGS. 3A-7, as further describedbelow. The top edge ring 802 may be disposed on a middle edge ring 806,which may be disposed on a bottom edge ring 808. The lift pin receivingelement 803 includes ‘V’-shaped side walls 810, 812 that extend inwardtowards the flat recessed portion 804. The flat recessed portion 804 iscup-shaped and includes side walls 814, 816 that are part of acontinuous slot-shaped side wall 818 (shown in FIG. 9) of the flatrecessed portion 804. FIG. 9 shows the lift pin receiving element 803.The flat recessed portion 804 further includes a flat top surface 820.

A lift pin 822 may be disposed in the lift pin receiving element 803 andcontacts top portions of the side walls 810, 812. The lift pin 822 doesnot contact the flat recessed portion 804. A top portion 824 of the liftpin 822 may protrude into an open area defined by the flat recessedportion 804. The top portion 824 may have a top flat surface, as shown.The lift pin receiving element 803, as shown in FIG. 9, further includeshalf conically shaped ends 830, 832, which are adjacent the side walls810, 812.

FIG. 10 shows a portion 1000 of an edge ring stack illustrating anexample of a top edge ring 1001 having a lift pin receiving element 1004in the form of a divot. The edge ring stack includes edge rings 1001,1002, 1003. The divot 1004 may include a chamfered side wall 1006 and ahemi-spherically shaped portion 1010. A top portion 1012 of a lift pin1014 may be hemi-spherically shaped and be disposed in thehemi-spherically shaped portion 1010. The portions 1010, 1012 may havetop flat surfaces, as shown. FIG. 11 shows the divot 1004 andillustrates the chamfered side wall 1006 and the hemi-spherically shapedportion 1010.

FIG. 12 shows a portion 1200 of an edge ring assembly 1201, substratesupport 1202 and substrate 1204 illustrating an example of a top edgering 1206 with a lift pin receiving element 1208 in the form of a groovehaving a recessed top portion 1210 with quarter spherically shaped ends1212, 1214. The portion 1200 may be similar to the portion 300 of FIG.3A, but includes the top edge ring 1206 having the lift pin receivingelement 1208 instead of the groove 322. FIG. 13 shows the lift pinreceiving element 1208. The lift pin receiving element 1208 includes‘V’-shaped side walls 1320, 1322, conically shaped end walls 1324, 1326,a ‘U’-shaped top wall 1328 and the quarter spherically shaped ends 1212,1214.

FIG. 14 shows a portion 1400 of an edge ring assembly 1402, a substratesupport 1404 and substrate 1406 illustrating incorporation of stabilityelements 1408, 1410. The stability elements 1408, 1410 are disposedrespectively within a top edge ring 1412 and a substrate support 1414.Although two stability elements are shown, any number of stabilityelements may be included. The top edge ring 1412 may include three ormore stability elements. Similarly, the substrate support 1414 mayinclude three or more stability elements. In one embodiment, thestability elements of the top edge ring 1412 are disposed 120° apartfrom each other. In one embodiment, the stability elements of thesubstrate support 1414 are disposed 120° apart from each other. Thestability elements may include and/or be implemented as springs.

The stability element 1408 is disposed in an inner pocket 1430 of thetop edge ring 1412 and applies pressure on an outer peripheral surface1432 of the edge ring 1416. The stability elements 1410 is disposed inan outer pocket 1440 of the substrate support 1414 and applies pressureon an inner surface 1442 of the edge ring 1416. Although stabilityelements are shown as being disposed in the top edge ring 1412 and thesubstrate support 1410, the stability elements may be located in otheredge rings, such as in the edge ring 1416.

In one embodiment, the stability elements are included without use oflift pin receiving elements in the top edge ring 1412. Tops of lift pinsmay abut a bottom inner surface 1420 of the top edge ring 1412. Inanother embodiment, the stability elements are incorporated incombination with lift pin receiving elements, such as the lift pinreceiving elements shown in FIGS. 1-13, 15-21 and 25.

FIG. 15 shows a portion 1500 of an edge ring assembly 1502, a substratesupport 1504 and a substrate 1506. The edge ring assembly 1502 includesa top edge ring 1508, an inner stabilizing edge ring 1510, an edge ringstack 1512, and a liner 1514. The edge ring stack 1512 includes an outerperipheral edge ring 1520, a middle edge ring 1522, and a bottom edgering 1524. The substrate support 1504 includes a top plate 1526 and abaseplate 1532. A lift pin 1534 is received in a shield 1538. The liftpin 1534 extends through a channel 1540 of the base plate 1532. Theshield 1538 is disposed on the base plate 1532 and extends through holes1542, 1544 and 1546 respectively in the edge rings 1524, 1522, 1520. Theshield 1538 protects an upper portion of the lift pin 1534 from erosion.The liner 1514 is annular-shaped and disposed outside of and protectsfrom erosion an outer periphery of the edge rings 1522, 1524 and abottom of an outer periphery of the outer peripheral edge ring 1520.

The top edge ring 1508 includes peripherally located lift pin receivingelements (one lift pin receiving element 1550 is shown). In the exampleshown, the lift pin receiving elements are in the form of notcheslocated at an outer bottom periphery of the top edge ring 1508. Lift pinreceiving elements of a different style may be incorporated. Examples ofthe notches are shown in FIGS. 16-18. The lift pin 1534 is moved upwardin the base plate 1532 and the shield 1538 and into the lift pinreceiving element 1550 to raise the top edge ring 1508. The top edgering 1508 may be raised, such that a bottom surface 1552 of the top edgering 1508 is above a top surface 1554 of the substrate 1506. As anexample, the top edge ring 1508 may be raised 0.24″-0.60″. In anembodiment, the top edge ring 1508 is raised 0.15″-0.2″ duringprocessing of the substrate 1506. Raising the top edge ring 1508 movesand shapes a plasma sheath located above the substrate 1506 and the topedge ring 1508, which affects how ions are directed at the substrate1506. The higher the top edge ring 1508 is raised relative to thesubstrate 1506, the more a tilt angle of the plasma sheath is changed.Example tilt angles are shown in FIGS. 20-21. The top edge ring 1508 maybe raised up to a first level during processing. The top edge ring 1508may be raised up to a second level to be removed via an arm, asdescribed above. The second level may be higher than the first level.

The stabilizing edge ring 1510 includes a first top surface 1560 and asecond top surface 1562 and an instep 1564. The first top surface 1560is disposed under the substrate 1506. The second top surface 1562 isdisposed under the top edge ring 1508. The first top surface 1560transitions to the second top surface 1562 via the instep 1564. As anexample, a height of the instep 1564 from the second top surface 1562 tothe first top surface 1560 may be 0.30″. The instep 1564 (i) aids indeclamping the substrate 1506 from the substrate support 1504, (ii) aidsin maintaining positioning of the top edge ring 1508 includingpreventing the top edge ring from tilting relative to the substrate1506, and (iii) aids in preventing the substrate 1506 from moving underthe top edge ring 1508 when, for example, the substrate 1506 is notclamped to the substrate support 1504.

As an example, the edge rings 1508 and 1520 may be formed of anon-volatile material, such as quartz. The edge ring 1510 may be formedof a volatile material, such as silicon carbide and/or sapphire. Theedge rings 1522 and 1524 may be formed of a volatile material, such asalumina. The liner 1514 may be formed of a metallic material.

FIGS. 16-17 show portions 1600, 1602 of the top edge ring 1508illustrating the lift pin receiving element 1550. The lift pin receivingelement 1550 is shown in the form of a notch and includes ‘V’-shapedside walls 1604, 1606, and a half conically shaped (or quarterspherically shaped) end 1608. The lift pin receiving element 1550 mayinclude a beveled edge 1610 along a bottom outer portion of the lift pinreceiving element 1550. A lift pin 1620 is shown as being received inthe lift pin receiving element 1550. The lift pin receiving element 1550extends from a peripheral edge 1622 of the top edge ring 1508. The liftpin receiving element 1550 may include a vertex portion 1624 that may beflat, cup-shaped, and/or rounded. The ‘V’-shaped side walls 1604, 1606may be beveled upward near the peripheral edge to provide beveledsections 1626, 1628.

FIG. 18 shows the top edge ring 1508, which may include three or more ofthe lift pin receiving elements. In FIG. 18, three lift pin receivingelements 1800 are shown, one of which may be the lift pin receivingelement 1550. The three lift pin receiving elements 1800 may be 120°spaced apart along a peripheral edge of the top edge ring 1508.

FIG. 19 shows an edge ring system 1900, a substrate support 1902 and asubstrate 1904. The edge ring system 1900 includes a collapsible edgering assembly 1906, an upper outer edge ring 1908, a lower outer edgering 1910, an alignment pin 1911, and a liner 1912. The alignment pin1911 maintains alignment between the edge rings 1908, 1910. The liner1912 protects the outer periphery of the lower outer edge ring 1910 anda bottom portion of the upper outer edge ring 1908 from erosion. Thesubstrate support 1902 includes a top plate 1926, seals 1928, 1930, anda baseplate 1932. A lift pin 1938 extends through the edge rings 1908,1910 and into the collapsible edge ring assembly 1906.

The collapsible edge ring assembly 1906 includes a top edge ring 1940,one or more intermediate edge rings (intermediate edge rings 1942, 1944,1946 are shown), and three or more ring alignment and spacing elements(one ring alignment and spacing element 1948 is shown). The edge rings1940, 1942, 1944, 1946 provide tuning using multiple edge rings. Thisincreases a tuning range over a single edge ring design because the topedge ring 1940 is able to be lifted to an increased height withoutplasma flowing under the top edge ring 1940. The multiple edge rings maybe sized and lifted via lift pins to be replaced while a correspondingprocessing chamber is under vacuum. The ring alignment and spacingelements are incorporated to maintain lateral (or radial) alignment ofthe edge rings 1940, 1942, 1944, 1946 relative to each other and tocontrol vertical spacing between the edge rings 1940, 1942, 1944, 1946.Alignment of the edge rings 1940, 1942, 1944, 1946 is aided by“V’-shaped grooves of lift pin receiving elements (one lift pinreceiving element 1950 is shown) in the top edge ring 1940. The top edgering 1940 includes one or more lift pin receiving elements. The lift pinreceiving elements may be implemented as any of the lift pin receivingelements disclosed in, for example, FIGS. 3A-13. The edge rings 1942,1944, 1946 include holes 1952, 1954, 1956 through which the lift pin1938 is passed.

The ring alignment and spacing elements may extend at least partiallyinto and/or through, connect to, adhere to, be pressed againstcorresponding portions of the edge rings 1940, 1942, 1944, 1946. Thering alignment and spacing elements may be collapsible. The ringalignment and spacing elements may have concertinaed walls (or be“accordion-like”) and/or have telescopic features that allow the ringalignment and spacing elements to be compressed and expanded. The ringalignment and spacing elements may include interlocking elements similarto a telescopic device, such that each section of the ring alignment andspacing elements interlocks with one or more adjacent sections. Examplesof ring alignment and spacing elements are shown in FIGS. 22A-26. Thering alignment and spacing elements allow corresponding lift pins (e.g.,the lift pin 1938) to directly lift the top edge ring 1940 followed byindirectly and successively lifting the intermediate edge rings 1942,1944, 1946 as a result of the edge rings 1940, 1942, 1944, 1946 beingconnected via the ring alignment and spacing elements. The edge rings1940, 1942, 1944, 1946 are lifted to different heights. In oneembodiment, each of the ring alignment and spacing elements has arespective amount of wrappings to provide a respective amount ofseparation between corresponding edge rings. The ring alignment andspacing elements may provide a predetermined spacing pattern of the edgerings 1940, 1942, 1944, 1946. Different spacing patterns may be providedfor different applications, recipes, etching patterns, etc.

The ring alignment and spacing elements have a fully retracted state, afully expanded state, and multiple intermediate (or partially expanded)states therebetween. While in the fully retracted state, the ringalignment and spacing elements may be in contact with each other or havea minimum amount of separation between adjacent ones of the ringalignment and spacing elements. While in the fully expanded state, theedge rings 1940, 1942, 1944, 1946 are separated from each other and havea maximum amount of separation between adjacent ones of the edge rings1940, 1942, 1944, 1946. While being extracted, the top edge ring 1940 islifted first without movement of the intermediate edge rings 1942, 1944,1946. When a distance between the top edge ring 1940 and a first one ofthe intermediate edge ring 1942 is at a maximum, then the firstintermediate edge ring 1942 is lifted. A similar process occurs for eachsuccessive intermediate edge ring. Although a particular number of edgerings are shown as being part of the collapsible edge ring assembly1906, two or more edge rings may be included.

As an example, the edge ring 1908 may be formed of a non-volatilematerial, such as quartz. The edge ring 1910 may be formed of a volatilematerial, such as alumina. The liner 1912 may be formed of a metallicmaterial. The edge rings 1940, 1942, 1944, 1946 may be formed of anon-volatile material such as quartz. The ring alignment and spacingelement 1948 may be formed of volatile material such as sapphire.

The ring alignment and spacing element 1948 may limit maximum separationdistances between the edge rings 1940, 1942, 1944, 1946 to preventplasma from flowing between the edge rings 1940, 1942, 1944, 1946. Flowof plasma between the edge rings 1940, 1942, 1944, 1946 can reduceand/or eliminate the plasma sheath tunability aspects associated withthe vertical movement of the top edge ring 1940. Also, the lift pin 1938may be limited from lifting the bottom most intermediate edge ring 1946more than a predetermined distance above a top surface 1960 of thesubstrate 1904. As an example, the system controller 160 of FIG. 1 maylimit the amount of movement of the lift pin 1938 to limit vertical liftof the bottom most intermediate edge ring 1946 to prevent plasma fromflowing between the edge ring 1946 and the stabilizing edge ring 1962.Flow of plasma between the edge rings 1946 and 1962 can also reduceand/or eliminate the plasma sheath tunability aspects associated withthe vertical movement of the top edge ring 1940. By limiting the maximumseparation distances between adjacent pairs of the edge rings 1940,1942, 1944, 1946, 1962, flow of plasma between the adjacent pairs isprevented.

FIGS. 20-21 show a portion 2000 of the collapsible edge ring assembly1906 of FIG. 19, which includes the edge rings 1940, 1942, 1944, 1946.The collapsible edge ring assembly 1906 is shown in (i) a firstpartially expanded state and having a first corresponding plasma sheathtilt angle α₁, and (ii) a second partially expanded state and having asecond corresponding plasma sheath tilt angle α₂. The collapsible edgering assembly 1906 is shown in a more expanded state in FIG. 21 than inFIG. 20. For this reason, the plasma sheath tilt angle α is larger forthe example of FIG. 21 than for the example of FIG. 20. The plasmasheath angle α may refer to an angle between (i) a vertical line 2001extending through an inner peripheral edge 2002 of the top edge ring1940 and (ii) a line 2004 representing an approximate periphery ofplasma vertically along a periphery of the edge rings 1940, 1942, 1944and 1946.

If a width WC of a cross-section of each of the edge rings 1940, 1942,1944, 1946 is the same, then gaps between the edge rings 1940, 1942,1944, 1946 and plasma 2010 may increase from a top surface of the topedge ring 1940 down to a bottom surface of the bottom most intermediateedge ring 1946. In one embodiment, the widths of the cross-sections ofthe edge rings 1940, 1942, 1944, 1946 may increase from the top edgering 1940 down to the bottom most intermediate edge ring 1946, suchthat: the cross-section of the edge ring 1946 is wider than thecross-section of the edge ring 1944; the cross-section of the edge ring1944 is wider than the cross-section of the edge ring 1942; and thecross-section of the edge ring 1942 is wider than the cross-section ofthe edge ring 1940. Also, due to the increased size of the gaps forlower edge rings, the tolerances in freedom of radial movement of loweredge rings is higher than the tolerances in freedom of radial movementof higher edge rings.

By controlling the lift positions of the edge rings 1940, 1942, 1944,1946, the shape and tilt angle α of the plasma sheath is adjusted. Themore the edge rings 1940, 1942, 1944, 1946 are lifted, the more theshape and tilt angle α are adjusted. This provides controllable etchtuning near a periphery (or circumferential edge) of the substrate 1904to within 0.039″. As the top edge ring 1940 is lifted, the tilt angle αis increased and an area of the top surface 1960 that is etched isdecreased. This increases a peripheral range of etching and how the topsurface 1960 of the substrate 1904 within the peripheral range isetched.

FIGS. 22A-22B show a collapsible edge ring assembly 2200 including aring alignment and spacing element 2202 that is inner disposed and in acollapsed state in FIG. 22A and in an expanded state in FIG. 22B. Thecollapsible edge ring assembly 2200 may include edge rings 2210, 2212,2214, 2216. The ring alignment and spacing element 2202 is “pyramid”shaped and tiered to include multiple levels 2217, 2219, 2221, 2223;each level for a respective one of the edge rings 2210, 2212, 2214,2216. As the top edge ring 2210 is lifted, the ring alignment andspacing element 2202 expands, maintains alignment between the edge rings2210, 2212, 2214, 2216, and lifts the edge rings 2210, 2212, 2214, 2216successively.

As an example, the edge rings 2210, 2212, 2214, 2216 may havethicknesses T1-T4 and the tiers of the ring alignment and spacingelement 2202 may have heights H1-H4. In one embodiment, the thicknessesT2-T4 are equal to each other. In another embodiment, the thicknessesT2-T4 are different. In yet another embodiment, the thickness T2-T4increase in size from T2 to T4, such that T4>T3>T2. In an embodiment,the heights H1-H3 are equal to each other. The levels 2217, 2219, 2221,2223 have widths W1, W2, W3, W4. The lower the level, the larger thewidth, such that W4>W3>W2>W1.

FIGS. 23A and 23B show a collapsible edge ring assembly 2300 includingedge rings 2302, 2304, 2306 and ring alignment and spacing elements2308, 2309, 2310 (the ring alignment and spacing element 2308 is shownin FIG. 1). The ring alignment and spacing element 2308 is shown in FIG.23A in an expanded state. The ring alignment and spacing elements 2308,2309, 2310 are located at a periphery of the edge rings 2302, 2304,2306. Each of the ring alignment and spacing elements 2308, 2309, 2310may be ‘comb’-shaped and include fingers 2320, 2322, 2324 respectivelyfor lifting the edge rings 2302, 2304, 2306. The fingers 2320, 2322,2324 extend radially inward from a main member 2326. Although three edgerings and three fingers are shown for each ring alignment and spacingelement, two or more edge rings and two or more fingers may be included.The fingers 2320, 2322, 2324 may be configured to interlock with,connect to, fit in notches of, and/or hold the respective edge rings2302, 2304, 2306. Although not shown, a lift pin may extend through oneor more of the edge rings (e.g., the edge rings 2304, 2306) and into alift pin receiving element of an upper most edge ring (e.g., the edgering 2302). The lift pin may directly lift the edge ring 2302 followedby indirectly lifting edge rings 2304, 2306 due to being held by,connected to, and/or sitting on the fingers 2320, 2322, 2324 of the ringalignment and spacing element 2308. The fingers 2320, 2322, 2324 maydecrease in length from the uppermost finger 2320 to the bottom mostfinger 2324, such that the uppermost finger 2320 is shorter than theintermediate finger 2322, which is shorter than the bottom most finger2324.

FIG. 24 shows an edge ring system 2400, a substrate support 2402 and asubstrate 2404. The edge ring system 2400 includes a collapsible edgering assembly 2406 that includes edge rings 2408, 2410, 2412, 2414lifted by a stepped outer edge ring 2416, which may be referred to as aring alignment and spacing element. A lift pin 2418 lifts the steppedouter edge ring 2416, which in turn lifts the edge rings 2408, 2410,2412, 2414. Radial peripheral ends 2420, 2422, 2424, 2426 of the edgerings 2408, 2410, 2412, 2414 are disposed on steps 2430, 2432, 2434,2436 of the stepped outer edge ring 2416. The lift pin 2418 may pushupwards on a flange 2450 of the stepped outer edge ring 2416. The flange2450 extends radially inward from the step 2436 and between an edge ring2452 and the lift pin 2418. The edge ring 2452 is similar to the edgerings 310 and 1510 of FIGS. 3A and 15. Although not shown, the flange2450 may include a lift pin receiving element to receive a top end ofthe lift pin 2418, as described above. The stepped outer edge ring 2416may be included in a stack of edge rings as shown and be disposed on anintermediate edge ring 2452, which is disposed on a bottom edge ring2454.

The stepped outer edge ring 2416 may be formed of a non-volatilematerial such as quartz. The intermediate edge ring 2452 may be formedof a volatile material such as sapphire. The bottom edge ring 2454 maybe formed of a non-volatile material such as quartz.

FIG. 25 shows an edge ring assembly 2500, a substrate support 2502 and asubstrate 2504. The edge ring assembly 2500 includes a top edge ring2506, an intermediate edge ring 2508, a stabilizing edge ring 2510, anedge ring stack 2512 and a liner 2514. The edge ring stack includes edgerings 2516, 2518, 2520, which are similar to edge rings 1520, 1522, 1524of FIG. 15. The edge ring 2506 is similar to the edge ring 1508, but maybe thinner than the edge ring 1508 due to the incorporation of the edgering 2508.

The edge rings 2506, 2508 may be lifted by three or more lift pins (onelift pin 2530 is shown). The lift pins may each include one or moresteps for lifting respectively one or more edge rings. For example, thelift pin 2530 is shown as including a step 2532, which is used to liftthe edge ring 2508. A tip 2534 of the lift pin 2530 is moved through ahole 2536 in the edge ring 2508 and is received in a lift pin receivingelement 2538. The lift pin 2530 includes a first portion 2540 having afirst diameter D1 and a second portion 2542 having a second diameter D2,which is greater than D1. The lift pin 2530 may have any number of stepsto lift any number of edge rings. This provides increased versatilityand processing sensitivity by allowing various numbers of edge rings tobe incorporated and lifted to respective predetermined heights. The liftpin 2530 may extend through a base plate 2544 and a shield 2552, whichmay be similar to the shield 1538 of FIG. 15.

As an alternative to the example shown in FIG. 25, multiple sets of liftpins may be used, where a first set of lift pins raise a first edge ring(e.g., the top edge ring 2506) and a second set of lift pins raise asecond edge ring (e.g., the intermediate edge ring 2508). In thisexample, the second edge ring may have holes, similar to the holes 2536,for both of the sets of lift pins. The first set of lift pins may notraise the intermediate edge ring 2508 and/or one or more edge ringsdisposed below the top edge ring 2506. The second set of lift pins maynot raise the top edge ring 2506. The second set of lift pins, dependingif stepped, may raise one or more edge rings disposed below theintermediate edge ring 2508. Any number of sets of lift pins, edgerings, and corresponding sets of holes may be included. As anotherexample, the one or more edge rings that are disposed below the top edgering 2506 may include lift pin receiving elements for receiving acorresponding set of lift pins. As a result, kinematic coupling may beprovided between each edge ring being lifted and a respective set oflift pins.

FIG. 26 shows a collapsible edge ring assembly 2600 including a ringalignment and spacing element 2602 with telescopic sections 2604, 2606,2608, 2610. Each of the telescopic sections 2604, 2606, 2608, 2610 maybe used to attach to and/or lift a corresponding edge ring, such as edgerings 2612, 2614, 2616, 2618. The telescopic sections 2604, 2606, 2608slide partially into the telescopic sections 2606, 2608, 2610,respectively. The telescopic sections 2604, 2606, 2608, 2610 areinterlocking sections.

The examples disclosed herein have kinematic coupling and anti-walkfeatures, as well as edge ring assemblies for increased tuning. Thekinematic coupling disclosed herein may, as an example, maintain topedge ring positioning relative to a substrate to within 100 microns. Theinclusion of kinematic coupling features improves positioning andcentering of top edge rings by an order of 2 over traditionalpositioning and centering techniques. Inclusion of the ‘V”-shapedgrooves provides kinematic coupling without over-constraining an edgering or binding an edge ring kit. As a result, a top edge ring does notneed constellations to center and provide consistent alignment. The edgering assemblies include edge rings that are actuated and lifted tophysically manipulate plasma by adjusting tilt angles of a plasma sheathover top surfaces of a substrate, which in turn affects criticaldimensioning and etch rates of the substrate.

Designing edge rings for higher radio frequency (RF) and direct current(DC) power levels can require a thorough mapping of datums and relativeoffsets to calculate each dimension and associated gap betweencomponents to avoid over constraining while minimizing sizes of the gaps(see Paschen's Law). To improve on extreme edge (EE) uniformity of awafer, edge rings are lifted as disclosed herein and have an increasedamount of tuning range. The effective pocket height may be varied withina single process of the wafer. The edge rings may be actuated graduallyover time for wafers including memory components to compensate forerosion such that a single edge ring kit is able to maintain apredetermined level of EE uniformity for increased mean time betweencleans (MTBCs). This reduces costs of operation.

The foregoing description is merely illustrative in nature and is in noway intended to limit the disclosure, its application, or uses. Thebroad teachings of the disclosure can be implemented in a variety offorms. Therefore, while this disclosure includes particular examples,the true scope of the disclosure should not be so limited since othermodifications will become apparent upon a study of the drawings, thespecification, and the following claims. It should be understood thatone or more steps within a method may be executed in different order (orconcurrently) without altering the principles of the present disclosure.Further, although each of the embodiments is described above as havingcertain features, any one or more of those features described withrespect to any embodiment of the disclosure can be implemented in and/orcombined with features of any of the other embodiments, even if thatcombination is not explicitly described. In other words, the describedembodiments are not mutually exclusive, and permutations of one or moreembodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example,between modules, circuit elements, semiconductor layers, etc.) aredescribed using various terms, including “connected,” “engaged,”“coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and“disposed.” Unless explicitly described as being “direct,” when arelationship between first and second elements is described in the abovedisclosure, that relationship can be a direct relationship where noother intervening elements are present between the first and secondelements, but can also be an indirect relationship where one or moreintervening elements are present (either spatially or functionally)between the first and second elements. As used herein, the phrase atleast one of A, B, and C should be construed to mean a logical (A OR BOR C), using a non-exclusive logical OR, and should not be construed tomean “at least one of A, at least one of B, and at least one of C.”

In some implementations, a controller is part of a system, which may bepart of the above-described examples. Such systems can comprisesemiconductor processing equipment, including a processing tool ortools, chamber or chambers, a platform or platforms for processing,and/or specific processing components (a wafer pedestal, a gas flowsystem, etc.). These systems may be integrated with electronics forcontrolling their operation before, during, and after processing of asemiconductor wafer or substrate. The electronics may be referred to asthe “controller,” which may control various components or subparts ofthe system or systems. The controller, depending on the processingrequirements and/or the type of system, may be programmed to control anyof the processes disclosed herein, including the delivery of processinggases, temperature settings (e.g., heating and/or cooling), pressuresettings, vacuum settings, power settings, radio frequency (RF)generator settings, RF matching circuit settings, frequency settings,flow rate settings, fluid delivery settings, positional and operationsettings, wafer transfers into and out of a tool and other transfertools and/or load locks connected to or interfaced with a specificsystem.

Broadly speaking, the controller may be defined as electronics havingvarious integrated circuits, logic, memory, and/or software that receiveinstructions, issue instructions, control operation, enable cleaningoperations, enable endpoint measurements, and the like. The integratedcircuits may include chips in the form of firmware that store programinstructions, digital signal processors (DSPs), chips defined asapplication specific integrated circuits (ASICs), and/or one or moremicroprocessors, or microcontrollers that execute program instructions(e.g., software). Program instructions may be instructions communicatedto the controller in the form of various individual settings (or programfiles), defining operational parameters for carrying out a particularprocess on or for a semiconductor wafer or to a system. The operationalparameters may, in some embodiments, be part of a recipe defined byprocess engineers to accomplish one or more processing steps during thefabrication of one or more layers, materials, metals, oxides, silicon,silicon dioxide, surfaces, circuits, and/or dies of a wafer.

The controller, in some implementations, may be a part of or coupled toa computer that is integrated with the system, coupled to the system,otherwise networked to the system, or a combination thereof. Forexample, the controller may be in the “cloud” or all or a part of a fabhost computer system, which can allow for remote access of the waferprocessing. The computer may enable remote access to the system tomonitor current progress of fabrication operations, examine a history ofpast fabrication operations, examine trends or performance metrics froma plurality of fabrication operations, to change parameters of currentprocessing, to set processing steps to follow a current processing, orto start a new process. In some examples, a remote computer (e.g. aserver) can provide process recipes to a system over a network, whichmay include a local network or the Internet. The remote computer mayinclude a user interface that enables entry or programming of parametersand/or settings, which are then communicated to the system from theremote computer. In some examples, the controller receives instructionsin the form of data, which specify parameters for each of the processingsteps to be performed during one or more operations. It should beunderstood that the parameters may be specific to the type of process tobe performed and the type of tool that the controller is configured tointerface with or control. Thus as described above, the controller maybe distributed, such as by comprising one or more discrete controllersthat are networked together and working towards a common purpose, suchas the processes and controls described herein. An example of adistributed controller for such purposes would be one or more integratedcircuits on a chamber in communication with one or more integratedcircuits located remotely (such as at the platform level or as part of aremote computer) that combine to control a process on the chamber.

Without limitation, example systems may include a plasma etch chamber ormodule, a deposition chamber or module, a spin-rinse chamber or module,a metal plating chamber or module, a clean chamber or module, a beveledge etch chamber or module, a physical vapor deposition (PVD) chamberor module, a chemical vapor deposition (CVD) chamber or module, anatomic layer deposition (ALD) chamber or module, an atomic layer etch(ALE) chamber or module, an ion implantation chamber or module, a trackchamber or module, and any other semiconductor processing systems thatmay be associated or used in the fabrication and/or manufacturing ofsemiconductor wafers.

As noted above, depending on the process step or steps to be performedby the tool, the controller might communicate with one or more of othertool circuits or modules, other tool components, cluster tools, othertool interfaces, adjacent tools, neighboring tools, tools locatedthroughout a factory, a main computer, another controller, or tools usedin material transport that bring containers of wafers to and from toollocations and/or load ports in a semiconductor manufacturing factory.

The foregoing description is merely illustrative in nature and is in noway intended to limit the disclosure, its application, or uses. Thebroad teachings of the disclosure can be implemented in a variety offorms. Therefore, while this disclosure includes particular examples,the true scope of the disclosure should not be so limited since othermodifications will become apparent upon a study of the drawings, thespecification, and the following claims. It should be understood thatone or more steps within a method may be executed in different order (orconcurrently) without altering the principles of the present disclosure.Further, although each of the embodiments is described above as havingcertain features, any one or more of those features described withrespect to any embodiment of the disclosure can be implemented in and/orcombined with features of any of the other embodiments, even if thatcombination is not explicitly described. In other words, the describedembodiments are not mutually exclusive, and permutations of one or moreembodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example,between modules, circuit elements, semiconductor layers, etc.) aredescribed using various terms, including “connected,” “engaged,”“coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and“disposed.” Unless explicitly described as being “direct,” when arelationship between first and second elements is described in the abovedisclosure, that relationship can be a direct relationship where noother intervening elements are present between the first and secondelements, but can also be an indirect relationship where one or moreintervening elements are present (either spatially or functionally)between the first and second elements. As used herein, the phrase atleast one of A, B, and C should be construed to mean a logical (A OR BOR C), using a non-exclusive logical OR, and should not be construed tomean “at least one of A, at least one of B, and at least one of C.”

In some implementations, a controller is part of a system, which may bepart of the above-described examples. Such systems can comprisesemiconductor processing equipment, including a processing tool ortools, chamber or chambers, a platform or platforms for processing,and/or specific processing components (a wafer pedestal, a gas flowsystem, etc.). These systems may be integrated with electronics forcontrolling their operation before, during, and after processing of asemiconductor wafer or substrate. The electronics may be referred to asthe “controller,” which may control various components or subparts ofthe system or systems. The controller, depending on the processingrequirements and/or the type of system, may be programmed to control anyof the processes disclosed herein, including the delivery of processinggases, temperature settings (e.g., heating and/or cooling), pressuresettings, vacuum settings, power settings, radio frequency (RF)generator settings, RF matching circuit settings, frequency settings,flow rate settings, fluid delivery settings, positional and operationsettings, wafer transfers into and out of a tool and other transfertools and/or load locks connected to or interfaced with a specificsystem.

Broadly speaking, the controller may be defined as electronics havingvarious integrated circuits, logic, memory, and/or software that receiveinstructions, issue instructions, control operation, enable cleaningoperations, enable endpoint measurements, and the like. The integratedcircuits may include chips in the form of firmware that store programinstructions, digital signal processors (DSPs), chips defined asapplication specific integrated circuits (ASICs), and/or one or moremicroprocessors, or microcontrollers that execute program instructions(e.g., software). Program instructions may be instructions communicatedto the controller in the form of various individual settings (or programfiles), defining operational parameters for carrying out a particularprocess on or for a semiconductor wafer or to a system. The operationalparameters may, in some embodiments, be part of a recipe defined byprocess engineers to accomplish one or more processing steps during thefabrication of one or more layers, materials, metals, oxides, silicon,silicon dioxide, surfaces, circuits, and/or dies of a wafer.

The controller, in some implementations, may be a part of or coupled toa computer that is integrated with the system, coupled to the system,otherwise networked to the system, or a combination thereof. Forexample, the controller may be in the “cloud” or all or a part of a fabhost computer system, which can allow for remote access of the waferprocessing. The computer may enable remote access to the system tomonitor current progress of fabrication operations, examine a history ofpast fabrication operations, examine trends or performance metrics froma plurality of fabrication operations, to change parameters of currentprocessing, to set processing steps to follow a current processing, orto start a new process. In some examples, a remote computer (e.g. aserver) can provide process recipes to a system over a network, whichmay include a local network or the Internet. The remote computer mayinclude a user interface that enables entry or programming of parametersand/or settings, which are then communicated to the system from theremote computer. In some examples, the controller receives instructionsin the form of data, which specify parameters for each of the processingsteps to be performed during one or more operations. It should beunderstood that the parameters may be specific to the type of process tobe performed and the type of tool that the controller is configured tointerface with or control. Thus as described above, the controller maybe distributed, such as by comprising one or more discrete controllersthat are networked together and working towards a common purpose, suchas the processes and controls described herein. An example of adistributed controller for such purposes would be one or more integratedcircuits on a chamber in communication with one or more integratedcircuits located remotely (such as at the platform level or as part of aremote computer) that combine to control a process on the chamber.

Without limitation, example systems may include a plasma etch chamber ormodule, a deposition chamber or module, a spin-rinse chamber or module,a metal plating chamber or module, a clean chamber or module, a beveledge etch chamber or module, a physical vapor deposition (PVD) chamberor module, a chemical vapor deposition (CVD) chamber or module, anatomic layer deposition (ALD) chamber or module, an atomic layer etch(ALE) chamber or module, an ion implantation chamber or module, a trackchamber or module, and any other semiconductor processing systems thatmay be associated or used in the fabrication and/or manufacturing ofsemiconductor wafers.

As noted above, depending on the process step or steps to be performedby the tool, the controller might communicate with one or more of othertool circuits or modules, other tool components, cluster tools, othertool interfaces, adjacent tools, neighboring tools, tools locatedthroughout a factory, a main computer, another controller, or tools usedin material transport that bring containers of wafers to and from toollocations and/or load ports in a semiconductor manufacturing factory.

What is claimed is:
 1. A first edge ring for a substrate support, thefirst edge ring comprising: an annular-shaped body sized and shaped tosurround an upper portion of the substrate support, wherein theannular-shaped body defines an upper surface, a lower surface, aradially inner surface, and a radially outer surface; and one or morelift pin receiving elements disposed along the lower surface of theannular-shaped body and sized and shaped to receive and providekinematic coupling with top ends respectively of three or more liftpins.
 2. The first edge ring of claim 1, comprising three lift pinreceiving elements disposed along the lower surface of theannular-shaped body.
 3. The first edge ring of claim 1, wherein: theannular-shaped body comprises an inner diameter; and the inner diameteris greater than an outer diameter of a top portion of the substratesupport.
 4. The first edge ring of claim 1, wherein the annular-shapedbody is formed at least partially of a non-volatile material.
 5. Thefirst edge ring of claim 1, wherein the one or more lift pin receivingelements include at least one groove.
 6. The first edge ring of claim 1,wherein the one or more lift pin receiving elements include at least oneV-shaped groove.
 7. The first edge ring of claim 6, wherein the at leastone ‘V’-shaped groove comprises walls at 60-120° relative to each other.8. The first edge ring of claim 6, wherein the at least one ‘V’-shapedgroove comprises walls at 45° relative to each other.
 9. The first edgering of claim 1, wherein: the one or more lift pin receiving elementscomprise at least one groove with a rounded vertex portion; and therounded vertex portion has a radius between 0.018″ and 0.035″.
 10. Thefirst edge ring of claim 1, wherein the one or more lift pin receivingelements include at least one of a rounded groove, a groove with halfconically shaped ends, or a groove with quarter hem i-spherically shapedends.
 11. The first edge ring of claim 1, wherein the one or more liftpin receiving elements include at least one divot.
 12. The first edgering of claim 1, wherein the one or more lift pin receiving elementsinclude chamfered side walls.
 13. The first edge ring of claim 1,wherein at least one of the one or more lift pin receiving elementsincludes a beveled portion to guide one of the three or more lift pinsinto the at least one of the one or more lift pin receiving elements.14. The first edge ring of claim 1, wherein the one or more lift pinreceiving elements include: a first lift receiving element with agroove; and a second lift pin receiving element with a divot.
 15. Thefirst edge ring of claim 1, wherein the one or more lift pin receivingelements include at least one groove with parallel side walls and a flator rounded top wall.
 16. The first edge ring of claim 1, wherein the oneor more lift pin receiving elements include only three lift pinreceiving elements.
 17. The first edge ring of claim 1, wherein the oneor more lift pin receiving elements include at least one notch disposedat a bottom periphery of the annular-shaped body.
 18. The first edgering of claim 17, wherein the at least one notch includes: a ‘V’-shapedgroove and a half conically shaped end; or a quarter hem i-sphericallyshaped end.
 19. The first edge ring of claim 1, wherein the one or morelift pin receiving elements are spaced 120° apart relative to a centerof the annular-shaped body.
 20. The first edge ring of claim 1, whereinthe one or more lift pin receiving elements include at least one grooveshaped to contact a corresponding one of the three or more lift pins atonly two points at a time.
 21. The first edge ring of claim 20, whereinthe at least one groove is shaped such that the corresponding one of thethree or more lift pins does not contact an uppermost portion or avertex portion of the at least one groove.
 22. A system comprising: thefirst edge ring of claim 1; and the three or more lift pins.
 23. Thesystem of claim 22, wherein: the one or more lift pin receiving elementscomprise at least one groove; and a ratio of a depth of the at least onegroove and a diameter of a corresponding one of the three or more liftpins is 1:1.
 24. The system of claim 22, wherein: the one or more liftpin receiving elements comprise at least one groove; and a ratio betweena depth of the at least one groove and a diameter of a corresponding oneof the three or more lift pins is between 10:1 and 1:8.
 25. The systemof claim 22, wherein: the one or more lift pin receiving elementscomprise at least one groove; the at least one groove includes sidewalls; and a ratio between the width of the groove and a diameter of acorresponding one of the three or more lift pins is between 20:1 and1:4.
 26. The system of claim 22, wherein: the one or more lift pinreceiving elements comprise at least one groove; and a ratio between adepth a corresponding one of the three or more lift pins is disposedinto the at least one groove and a depth of the at least one groove isbetween 10:1 and 1:8.
 27. The system of claim 22 wherein each of thethree or more lift pins is shaped to contact two points on surfaces of acorresponding one of the one or more lift pin receiving elements at atime and not contact a top surface or vertex portion of thecorresponding one of the one or more lift pin receiving elements. 28.The system of claim 22, wherein the three or more lift pins are formedat least partially of a volatile material.
 29. The system of claim 22,further comprising: at least one actuator for moving the three or morelift pins; and a controller configured to control operation of the atleast one actuator.
 30. The system of claim 22, further comprising: asecond edge ring; and at least one stabilizing element disposed in atleast one pocket of the annular-shaped body and applying pressure on thesecond edge ring.
 31. The system of claim 22, further comprising: asecond edge ring; and a third edge ring, wherein the first edge ring,the second edge ring and the third edge ring are arranged in a stack.32. The system of claim 31, wherein the second edge ring and the thirdedge ring are each formed at least partially of a volatile material. 33.The system of claim 22, further comprising a second edge ring comprisinga first top surface and a second top surface, wherein: the first topsurface is disposed adjacent a top surface of the substrate support andbelow a periphery of a substrate, wherein the first top surface isdisposed (i) at a level higher than a level of a bottom surface of thefirst edge ring, and (ii) radially inside the first edge ring; thesecond top surface is disposed below a portion of the first edge ring,the second top surface is disposed at a level lower than the level ofthe bottom surface of the first edge ring; and an instep from the firsttop surface to the second top surface.
 34. The system of claim 33,wherein the second edge ring is formed at least partially of a volatilematerial.
 35. A collapsible edge ring assembly for a substrate support,the collapsible edge ring assembly comprising: a plurality of edge ringsarranged in a stack, wherein at least one of the plurality of edge ringsis shaped and sized to surround an upper portion of the substratesupport, and wherein the plurality of edge rings comprise a top edgering and at least one intermediate edge ring; and three or more ringalignment and spacing elements contacting each of the plurality of edgerings and configured to maintain radial alignment and vertical spacingof the plurality of edge rings, wherein the three or more ring alignmentand spacing elements are configured to lift the at least oneintermediate edge ring while the top edge ring is lifted.
 36. Thecollapsible edge ring assembly of claim 35, wherein the three or morering alignment and spacing elements are sized to define spacing betweenadjacent ones of the plurality of edge rings during verticaldisplacement of the plurality of edge rings.
 37. The collapsible edgering assembly of claim 36, wherein the top edge ring comprises three ormore lift pin receiving elements sized and shaped to receive top ends ofthree or more lift pins.
 38. The collapsible edge ring assembly of claim37, wherein the at least one intermediate edge ring comprises holes forpassage of the three or more lift pins.
 39. The collapsible edge ringassembly of claim 35, wherein the plurality of edge rings have: a fullyretracted state, where the plurality of edge rings are in contact witheach other; and an expanded state, where the plurality of edge rings arespaced apart from each other.
 40. The collapsible edge ring assembly ofclaim 39, wherein a plasma sheath tilt angle associated with a peripheryof the top edge ring is smaller when the plurality of edge rings are inthe fully retracted state than when in the expanded state.
 41. Thecollapsible edge ring assembly of claim 35, wherein the three or morering alignment and spacing elements comprise only three ring alignmentand spacing elements spaced 120° apart from each other.
 42. Thecollapsible edge ring assembly of claim 35, wherein: at least one of thethree or more ring alignment and spacing elements is tiered to have aplurality of levels; and each of the plurality of levels lifts arespective one of the plurality of edge rings.
 43. The collapsible edgering assembly of claim 42, wherein: the plurality of levels haverespective steps; and heights of the respective steps are equal in size.44. The collapsible edge ring assembly of claim 42, wherein: theplurality of levels comprise a first level, a second level and a thirdlevel; the first level is disposed above the second level; the secondlevel is disposed above the third level; the third level is wider thanthe second level; and the second level is wider than the first level.45. The collapsible edge ring assembly of claim 35, wherein at least oneof the three or more ring alignment and spacing elements comprises aplurality of interlocking sections.
 46. The collapsible edge ringassembly of claim 35, wherein at least one of the three or more ringalignment and spacing elements comprises a plurality of telescopicsections.
 47. The collapsible edge ring assembly of claim 35, wherein:at least one of the three or more ring alignment and spacing elementscomprises a main member and a plurality of fingers; and the plurality offingers extend radially inward from the main member and lift respectiveones of the plurality of edge rings.
 48. The collapsible edge ringassembly of claim 47, wherein the plurality of fingers are configured tointerlock into or be disposed in notches of corresponding ones of theplurality of edge rings.
 49. The collapsible edge ring assembly of claim35, wherein: the at least one intermediate edge ring comprising a firstintermediate edge ring and a second intermediate edge ring; the firstintermediate edge ring has a first thickness; and the secondintermediate edge ring has a second thickness, the second thickness isgreater than the first thickness.
 50. The collapsible edge ring assemblyof claim 35, wherein: the three or more ring alignment and spacingelements are implemented as stepped lift pins; and the stepped lift pinsare configured to lift the plurality of edge rings.
 51. The collapsibleedge ring assembly of claim 35, further comprising a first set of liftpins, wherein: the three or more ring alignment and spacing elements areimplemented as a second set of lift pins; and the first set of lift pinsare configured to lift the top edge ring.
 52. The collapsible edge ringassembly of claim 35, wherein the plurality of edge rings are eachformed at least partially of a non-volatile material.
 53. Thecollapsible edge ring assembly of claim 35, wherein the three or morering alignment and spacing elements are each formed at least partiallyof a volatile material.
 54. A system comprising: the collapsible edgering assembly of claim 35; and a plurality of lift pins that extendthrough the at least one of the plurality of edge rings and into thethree or more lift pin receiving elements.
 55. The system of claim 54,further comprising: at least one actuator for moving the plurality oflift pins; and a controller configured to control operation of the atleast one actuator.
 56. A collapsible edge ring assembly for a substratesupport, the collapsible edge ring assembly comprising: a plurality ofedge rings arranged in a stack, wherein at least one of the plurality ofedge rings is shaped and sized to surround an upper portion of thesubstrate support, and wherein the plurality of edge rings comprise atop edge ring and at least one intermediate edge ring; and a steppedouter edge ring comprising a plurality of levels, wherein the pluralityof edge rings are disposed respectively on the plurality of levels,wherein the stepped outer edge ring is configured to maintain radialalignment and vertical spacing of the plurality of edge rings, andwherein the stepped outer edge ring is configured to lift the at leastone intermediate edge ring while the top edge ring is lifted.
 57. Thecollapsible edge ring assembly of claim 56, wherein: the plurality oflevels have respective steps; and heights of the respective steps areequal in size.
 58. The collapsible edge ring assembly of claim 56,wherein: the plurality of levels comprise a first level, a second leveland a third level; the first level is disposed above the second level;the second level is disposed above the third level; the third level hasan inner diameter that is greater than an inner diameter of the secondlevel; and the inner diameter of the second level is greater than aninner diameter of the first level.
 59. The collapsible edge ringassembly of claim 56, wherein the stepped outer edge ring is formed atleast partially of a non-volatile material.
 60. The collapsible edgering assembly of claim 56, wherein the stepped outer edge ring has aflange that extends radially inward to be disposed on a plurality oflift pins.
 61. A system comprising: the collapsible edge ring assemblyof claim 60; and the plurality of lift pins.
 62. The system of claim 61,further comprising a stabilizing edge ring disposed between theplurality of edge rings and the flange.
 63. The system of claim 62,further comprising the substrate support, wherein the stabilizing ringis disposed between the substrate support and the plurality of edgerings.
 64. The system of claim 62, wherein: the stabilizing edge ringcomprises a first top surface and a second top surface, wherein: thefirst top surface is disposed adjacent a top surface of the substratesupport and below a periphery of a substrate, wherein the first topsurface is disposed (i) at a level higher than a level of a bottomsurface of the first edge ring, and (ii) radially inside the first edgering; the second top surface is disposed below a portion of the firstedge ring, the second top surface is disposed at a level lower than thelevel of the bottom surface of the first edge ring; and an instep fromthe first top surface to the second top surface.